SATELLITE-TO-SATELLITE HANDOFF IN SATELLITE COMMUNICATIONS SYSTEM
First Claim
1. A method of operating a user terminal (UT) to perform a handoff operation from a first satellite to a second satellite, comprising:
- communicating with a first gateway over a forward link and a return link via the first satellite;
receiving a handoff message from the first gateway via the first satellite, wherein the handoff message comprises information sufficient for the UT to identify the second satellite for the handoff, and to determine a time for the handoff from the first satellite to the second satellite;
scheduling the handoff from the first satellite to the second satellite in accordance with the handoff message; and
executing the handoff from the first satellite to the second satellite.
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Accused Products
Abstract
Aspects of the disclosure provide a handoff procedure for a satellite communication system such as a broadband low-Earth orbit (LEO) satellite communication system. A gateway and a user terminal (UT) coordinate and schedule a satellite-to-satellite handoff in such a way that there are no messaging round-trip delays between the last return service link (RSL) packet transmitted from the user terminal to the source satellite and the first RSL packet transmitted from the user terminal to the target satellite. Therefore, an outage on the return link (from the user terminal to the gateway) can be limited to the actual time for moving the antenna feed from the source satellite to the target satellite. Furthermore, an outage on the forward link (from the gateway to the user terminal) can be limited to a single round-trip delay in addition to the time for moving the antenna feed.
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Citations
32 Claims
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1. A method of operating a user terminal (UT) to perform a handoff operation from a first satellite to a second satellite, comprising:
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communicating with a first gateway over a forward link and a return link via the first satellite; receiving a handoff message from the first gateway via the first satellite, wherein the handoff message comprises information sufficient for the UT to identify the second satellite for the handoff, and to determine a time for the handoff from the first satellite to the second satellite; scheduling the handoff from the first satellite to the second satellite in accordance with the handoff message; and executing the handoff from the first satellite to the second satellite. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 10, 31)
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9. (canceled)
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11. A user terminal (UT) configured to perform a handoff operation from a first satellite to a second satellite, comprising:
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a memory comprising handoff instructions; and a processor operatively coupled to the memory, wherein the processor and the memory are configured by the handoff instructions to; communicate with a first gateway over a forward link and a return link via the first satellite; receive a handoff message from the first gateway via the first satellite, wherein the handoff message comprises information sufficient for the UT to identify the second satellite for the handoff, and to determine a time for the handoff from the first satellite to the second satellite; schedule the handoff from the first satellite to the second satellite in accordance with the handoff message; and execute the handoff from the first satellite to the second satellite. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 20, 32)
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19. (canceled)
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21. A user terminal (UT) configured to perform a handoff operation from a first satellite to a second satellite, comprising:
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means for communicating with a first gateway over a forward link and a return link via the first satellite; means for receiving a handoff message from the first gateway via the first satellite, wherein the handoff message comprises information sufficient for the UT to identify the second satellite for the handoff, and to determine a time for the handoff from the first satellite to the second satellite; means for scheduling the handoff from the first satellite to the second satellite in accordance with the handoff message; and means for executing the handoff from the first satellite to the second satellite. - View Dependent Claims (22, 23, 24, 25)
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26. A non-transitory computer-readable medium, comprising a plurality of instructions for causing a user terminal (UT) to perform a handoff operation from a first satellite to a second satellite, the instructions cause the UT to:
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communicate with a first gateway over a forward link and a return link via the first satellite; receive a handoff message from the first gateway via the first satellite, wherein the handoff message comprises information sufficient for the UT to identify the second satellite for the handoff, and to determine a time for the handoff from the first satellite to the second satellite; schedule the handoff from the first satellite to the second satellite in accordance with the handoff message; and execute the handoff from the first satellite to the second satellite. - View Dependent Claims (27, 28, 29, 30)
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Specification